1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly, to a sense amplifier driver, which is not affected by an off-current in a semiconductor device manufactured in a high temperature, fast process, and a semiconductor device comprising the same. Further, the present invention relates to a method of generating a sense amplifier enable signal, which is not affected by an off-current, and a method of detecting data using the sense amplifier enable signal.
2. Description of the Related Art
FIG. 1 is a diagram of a conventional memory cell used in a semiconductor device. Referring to FIG. 1, a memory cell 10 is comprised of one transistor 11 and one capacitor 12.
In general, the transistor 11 has a gate connected to a word line WL and one end connected to a bit line BL. The capacitor 12 for storing data is connected between the other end of the transistor 11 and a ground voltage source VSS.
As a deep submicron technology is developed, a threshold voltage of the transistor 11 decreases to improve the performance of the transistor 11. Here, the performance of the transistor 11 can be represented by the amount of a current Idsat that can flow from the transistor 11 in a turn-on state.
However, when the threshold voltage of the transistor 11 decreases, the amount of a current (referred to as ‘on-current’ hereinafter) that can flow from the transistor 11 in a turn-on state increases, and the amount of a leakage current (referred to as ‘off-current’ hereinafter) that flows through the transistor in a turn-off state increases.
An off-current Ioff generally changes according to variations in voltage or type of process, for example, according to whether the process is a fast process or a slow process. Here, the fast process is a process for manufacturing a transistor having high on-current Idsat, and the slow process is a process for manufacturing a transistor having low on-current Idsat.
However, under specific conditions, for example, in a high-temperature, fast process, the off-current Ioff increases enough to affect the on-current Idsat. In particular, considering a difference between the on-current Idsat and the off-current Ioff during the high-temperature, fast process in a structure where a plurality of memory cells constitute an array, advantages taken by lowering threshold voltages of the memory cells considerably decrease.
When a memory device provided with a memory cell is designed, there is a limitation in lowering the threshold voltage of the memory cell due to such an off-current.